special circumstances

Definition from Nolo’s Plain-English Law Dictionary

In criminal cases, particularly homicides, actions of the accused or the situation under which the crime was committed for which state statutes allow or require imposition of a more severe punishment. "Special circumstances" in murder cases may well result in the imposition of the death penalty (in states with capital punishment). Such circumstances may include: rape, kidnapping or maiming prior to the killing, multiple deaths, killing a police officer or prison guard, or actions showing wanton disregard for life such as throwing a bomb into a restaurant. (See also: capital punishment)

Definition provided by Nolo’s Plain-English Law Dictionary.